MF265 draw bar mount spec

[keljan11]

Hey guys, I have an inherited an older MF 265. A few years ago, while baling hay, the draw bar mount managed to fall off the tractor. Anyways, managed to reinstall it and finish baling.
Ever since, almost every year, I have to check the mounting bolts at least twice a year to make sure it doesn't fall off again in the middle of cutting or baling hay. I've tried cleaning out the bolt holes with thread taps, using thread locker fluid, etc. The bolts are still falling out.
I realize the causes are the tight turns I make (but have no choice to make them in my fields), as well as the constant thrusting from the baler (again, not much choice).
My question is, are there torque specs for these mounting bolts? As the rear end appears to be aluminum or pot metal, I don't want to strip the threads, as I have to use the draw bar often.
I have done a fair amount of internet searches to find the specs. Any idea where to even find thes specs??
Thanx in advance

 

[JWR]

Good heavens, my MF2660 (newer machine) is very sturdy solid steel in that area. I always think of the older tractors being stronger, more metal in them, etc. Must be some sort of severe vibration or other issues going on there. Something's wrong and I cannot imagine what.

 

[keljan11]

Good heavens, my MF2660 (newer machine) is very sturdy solid steel in that area. I always think of the older tractors being stronger, more metal in them, etc. Must be some sort of severe vibration or other issues going on there. Something's wrong and I cannot imagine what.

As far as I can tell, it probably is cast iron. It is a 50 (??) year old tractor, and I just don't want to crack or strip something. I have done so on cast iron equipment at work in the past, and if I over-torqued these bolts, I'm guessing it could cause problems later on. This last cutting, I used my 1/2" air impact on it (on the lowest setting), and found a bolt on the ground right behind the baler when I stepped off to check something 12 hrs use later.
I believe the tractor was about 30 yrs old when we acquired it, and other than haying, we usually just use the fel or 3 pt hitch around the property.
I know there is a lot of continual thrusting force, from the baler counterweight spinning, on the drawbar, (and the tractor is a little long in the tooth, as the saying goes)

 

[Working on Rust]

I checked the service manual and did not find any specific torque for the draw bar bolts. Assuming they are grade 5, the torque table in the service manual says 270-300 foot pounds. They are suppose to be a tapered head bolt, a bit like a lug bolt, and I would think that that type of bolt is prone to working loose a little bit after being tightened, and in my experience with tapered head bolts they need to be torqued fairly often until they are tight and then they will stay tight after that.
If the bolt shoulders or the mounting holes in the drawbar frame or worn or wallowed, it is going to be very difficult to keep them tight and frequent torquing will be necessary until they stay tight.

Good luck and let us know what happens.

 

[zzvyb6]

1). Lock-Tite.
2). Drill small holes in the bolt heads and wire tie them together.
3). Make sure the hitch pin is exactly midway between the pto U-joint cross on the tractor and the U-joint cross on the baler's drive shaft. This gives the driveline approximately constant velocity and will minimize side-loading on the drawbar.
4). The 'thrusting' should not be very dramatic for a proper setup for the tractor and baler running at the right pto rpm. The hitch should be tight and allow for turning, rolling, and pitching angles, but no fore-aft slop.

 

[Dmacleo]

1). Lock-Tite.
2). Drill small holes in the bolt heads and wire tie them together.

about 15 years ago had to do similar to older long brand tractor due to many many (oh so many) tight turns when baling. on that unit we had thread length enough to double nut instead of drilling an wiring.

 

[keljan11]

1). Lock-Tite.
2). Drill small holes in the bolt heads and wire tie them together.
3). Make sure the hitch pin is exactly midway between the pto U-joint cross on the tractor and the U-joint cross on the baler's drive shaft. This gives the driveline approximately constant velocity and will minimize side-loading on the drawbar.
4). The 'thrusting' should not be very dramatic for a proper setup for the tractor and baler running at the right pto rpm. The hitch should be tight and allow for turning, rolling, and pitching angles, but no fore-aft slop.

I guess I mis-spoke. The thrusting I'm talking about comes from the baler plunger. When the tractor is even idled down when stopped with the pto on, the whole tractor rocks back and forth in time with the plunger. When running at 1500 rpms baling hay, I still feel the plunger action, although not nearly as bad. Because it makes small squares, the hitch is slightly off to the side so I don't drive on the raked winrows ( it's a NH 273 baler, also 40 ? yrs old). The pto shaft is a 2 piece shaft, to make up for the offset hitch I guess. The bolts are 3/4" X 2 1/4" long cap bolts with flat and lock washers, which I doubt are original bolts. I replaced them once the first time the mount fell off the tractor with the same style cap bolts that were there.

 

[WranglerX]

One thing I would do is check final torque on bolts by using a torque wrench or just manual test for tightness with the good old arm.... I use air impact to disassembly a lot but don't trust it for assembly.... Old school of socket on ratchet or breaker bar to validate toque...

Definitely something deeper wrong with assemble if torqueing bolts and using thread locker and it keeps coming loose...

 

[keljan11]

Well, in the past few times, I've used the breaker bar, socket (with a 4" extension), and just muscle to tighten the bolts. I'm thinking the blue locktite on the bolts isn't sticking because of all the oil, etc, inside the bolt holes. My hose connections on the fel have leaked a bit in the past, but have replaced the seals again this year. Haven't really wanted to use the red locktite in case I ever want/need to remove the drawbar mount, (but I suspect that won't be a problem with the bolts falling out anyways)
I used a torque wrench, set at 120 ft lbs this time, and will see how it works the next time I cut/bale hay probably next spring.
Thanx for all the thoughts, guys

 

[Working on Rust]

I think the torque should be over 200 ft lbs for 3/4 bolts like that. It also would be a good idea to retorque after a few heat cycles of the tractor.